Re: Offline enabling/disabling of data checksums

Michael Paquier <michael@paquier.xyz>

From: Michael Paquier <michael@paquier.xyz>
To: Michael Banck <michael.banck@credativ.de>
Cc: Magnus Hagander <magnus@hagander.net>, Fabien COELHO <coelho@cri.ensmp.fr>, Sergei Kornilov <sk@zsrv.org>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2019-03-18T08:13:01Z
Lists: pgsql-hackers

Attachments

On Fri, Mar 15, 2019 at 01:37:27PM +0100, Michael Banck wrote:
> Am Freitag, den 15.03.2019, 21:23 +0900 schrieb Michael Paquier:
>> Perhaps having them under --verbose makes more sense?
> 
> Well if we think it is essential in order to tell the user what happened
> in the case of an error, it shouldn't be verbose I guess.

I would still keep them to be honest.  I don't know, if others find
the tool too chatty we could always rework that part and tune it.

Please find attached an updated patch set, I have rebased that stuff
on top of my recent commits to refactor the control file updates.
While reviewing, I have found a problem in the docs (forgot a <para>
markup previously), and there was a problem with the parent path fsync
causing an interruption to not return the correct error code, and
actually we should just use durable_rename() in this case (if
--no-sync gets in then pg_mv_file() should be used of course).

I have also been thinking about what we could add in the
documentation, so this version adds a draft to describe the cases
where enabling checksums can lead to corruption when involving
multiple nodes in a cluster and tools doing physical copy of relation
blocks.

I have not done the --no-sync part yet on purpose, as that will most
likely conflict based on the feedback received for this version..
--
Michael

Commits

  1. Reorganize Notes section in documentation of pg_checksums

  2. Add option -N/--no-sync to pg_checksums

  3. Add options to enable and disable checksums in pg_checksums

  4. Refactor more code logic to update the control file

  5. Rename pg_verify_checksums to pg_checksums

  6. Fix cross-version compatibility checks of pg_verify_checksums

  7. Add routine able to update the control file to src/common/